Device for evacuating pumps



F. OBERASCHER DEVICE FOR EVACUATING PUMPS Filed June 1.9 192 8 30 of theexhaust Patented Oct. 7, 1930 UNITED STATES PATENT OFFICE Applicationfiled June 19, 1928, Serial No. 286,639, and in Austria June 30, 1927.

It has already been proposed to carry out the evacuation of rotary pumpsby means of an ejector, the suction effect of which would be broughtabout by the flow energy of a current of exhaust gases coming from aninternal combustion engine and passing through the ejector. In case of apump forming part of the firefighting outfit of a fire brigade vehiclethe exhaust gases of the motor itself may be used for operating theejector. Considering however that the pressure of the exhaust gases isnot high and that in consequence the ow energy available will berelatively small, it must be reckoned with that the suction effeetcaused in the ejector-by the exhaust gases will as a rule beinsuflicient and this all the more in proportion to the pressure los'sesoccurring between the exhaust side of the internal combustion engine andthe ejector.

The object of my invention is to improve the above mentioned device so tat a greater suction efiect is caused in the ejector by the energy offlow of the exhaust gases as coul hitherto be realized; it being afurther object of this invention to reduce the pressure losses of theexhaust gases before their entrance into the ejector so that inconsequence- 'by intensifying the suction eifect on the one hand and byreducing the losses of energy ases before their entrance into theejector on t e other hand-the total effect of the evacuating lilevice isimproved to such a degree, that a 'gher vacuum and accordingly a farhigher ump lift is obtainable as compared with a 1 other similar devicesknown. y

--The increase of. the suction efiect of the ejector is according to myinvention obtained by placin shock walls directly at the entrance of t eejector jet whereby the entrance edge of this jet is preferably made assharp as possible; The reduction of the energylosses of the'exhaustgases is brought about according to, my invention by locatingthe ejectoras near as possible to the exhaust side of the internal. combustionengine and evento join it directly to exhaust outlet. It isrecommendable to cool down the exhaust gases leaving the internalcombustion engine with a 50 high temperature before their entrance intothe ejector in order to prevent the organs of the evacuating device tobe damaged by the heat of the exhaust gases.

A mode of execution of the evacuating de' vice according to my inventionis presented partly in View and partly in section in Fig. 1, whilst Fig.2 illustrates on a larger scale a part of a section through the ejector.

1 refers to a part of an internal combustion engine, the design of whichis irrelevant for the present invention. The exhaust branch 2 of themotor 1 is connected to the distribution chamber 3 which, in case theexhaust gases are to be cooled, is provided with a cooling jacket 4fitted with the branches 5 and 6 for the admission and the outlet of thecooling medium f. i. water.

This distribution chamber 3 is closed by a plate 7 provided with twoopenings 8 and 9.

The opening 8 leads to the exhaust line 10, which may end in a silencer11. The opening 9 of the plate 7 is connected to the ejector 12consisting of the nozzle 13 (see also Fig. 2) and the difiusor 14leading into the open. Between the nozzle 13 and the difiusor a ringshaped hollow chamber 15 has been provided, whence a channel 16 leadsoutwards, being connected to the tube 17. This tube commu nicates withthe suction side of the rotary pump 18, the internal design of which isof no importance with regard to the present invention.

The distributionchamber 3 contains a ball 19, which by means of thesurrounding ring 20 can be moved to and fro in such a manner that italternately closes the openings 8 and 9, the ring 20 being actuated by arod 21 passing outwards through the chamber wall.

The result of this arrangement is that the exhaust gases enteringthrough the branch 2 into the distribution chamber 3- are compelled toflow according to the position of the ball 19 either throug the exhausttube 10 and the silencerll or through the ejector 12. The ejector nozzle13 comes out of a box shaped piece 22 containin an anteroom 23, which inthe direction of t e nozzle is closed by a wall placed transversely tothe direction of flow, which is provided with an opening leading to thenozzle channel. The exhaust gases entering the anteroom 23 of the box 22through the opening 9 will for the greatest part butt agalnst the shockwall 24, before they can reach the channel 25. When the exhaust gasesflow into the chamber 23 they undergo a bottling-up action prior totheir discharge through the channel 25. That is, instead of escapingfrom the chamber 23 at the same rate at which they are discharged intoit from the exhaust conduit 2 of the engine, the gases are permitted toescape through the channel 25, which is of considerably smallercross-section than the chamber 23. This reduction in the area of thechannel results in a backing-up and building-up of the pressure of thegases in the chamber 23. Hence, as the exhaust gases must enter theanteroorn 23 intermittently according to the cycle of operations of themotor 1, the butting of the exhaust gases against the wall 24 results inthe pressure and accordingly also in the energy of the exhaust gases inthe anteroom 23 being intermittently enhanced, so that the gases willflow out with a higher speed through the nozzle channel 25 towards thedifiusor 14, producing thereby a stronger suction effect in the ringshaped chamber 15, as if these intermittent pressure rises in theanteroom 23 would not take place.

The suction efi'ect of the ring chamber 15 propagates through thechannel 16 and the tube 17 reaching thereby the suction side of the pump18, which is rapidly evacuated.

By directly attaching the distribution chamber 3 to the exhaust branch 2of the motor 1, the energy embodied in the exhaust gases is exploited inthe ejector with the smallest possible loss.

. The effect of the shock wall 24 on the entrance side of the ejectornozzle 13 is particularly high, if the edge 25 between the shock wall 24and the nozzle channel 25 is sharp, that is when this place is notrounded off A cock 26 may be insertedin the pipe line 17 by which theevacuating-line of the pump 18 may be cut ofi, as soon as the pump oper-.ates regularly, whereby the exhaust gases need not flow through theejector 12. In this case the rod 21 is drawn out and the ball isbroughttobear upon the;.opening. 9,. so that the e ector 12 is shut out,whilst the exhaust 10 is opened. ThlS cock 26 may be connected 0 the rod21 by means of a coupling piece 27 so that a-connection is establishedbetween the opening and the closing of the cock'26 and the displacementof the ball 19, the ejector 12 being closed bythe'ball 19 at the samemoment as the pipe line 17 is out 01f by the cook 26 and vice-versa.

It goes without saying that the evacuation device described may bedesigned and constructed in difi'erent manners.

What I claim is:

1. In a device for evacuating pumps the combination of a pump, anejector having a nozzle, a diffuser and a suction room, an internalcombustion engine having an exhaust branch, a connection between theoutlet of said exhaust branch and the inlet of said ejector nozzle, saidconnection being adapted to lead the exhaust gases of said internalcombustion engine from its exhaust branch into the ejector nozzle sothat the ejector maybe operated by said exhaust gases, a suction conduitbetween the suction room of said ejector and the suction side of saidpump, and means for increasing the suction effect of the ejector, saidmeans comprising a wall located around the inlet of said ejector nozzleand transversely to the flow of the exhaust gases, whereby these gasesare compelled to butt against said wall.

2. In a device for evacuating pumps the combination of a pump, anejector having a nozzle, a diffuser and a suction room, an internalcombustion engine having an exhaust branch, a connection between theoutlet of said exhaust branch and the inlet of said ejector nozzle, saidconnection being adapted to leadthe exhaust gases of said internalcombustion engine from its exhaust branch into the ejector nozzle sothat the ejector may be operated by said exhaust gases, a suction conduit between the suction room of said ejector and the suction side ofsaid pump, and means for increasing the suction effect of the ejector,said means comprising an anteroom before the inlet of said ejectornozzle and a wall located around the inlet of said ejector nozzle andlimiting said anteroom transversely to the flow of the exhaust gases,whereby these gases are compelled to butt against said wall.

3. In a device for evacuating pumps the combination of a pump, anejector having a suction room, an internal combustion engine having anexhaust branch directly joined to the ejector so that said ejector maybe operated by the exhaust gases of said internal combustion engine, anda suction conduit between the suction room of said ejector and thesuction side of said pump.

4. In a device for evacuating pumps the combination of a pump, anejector having a nozzle and a suction room, an internal combustionengine-having an exhaust branch, a distribution chamber between theoutlet of said exhaust branch and the inlet of said ejector nozzle, saiddistribution chamber having an outlet leadin to the open air, saiddistribution chamber urther being adapted to lead the exhaust gases ofsaid internal combustion engine from its exhaust branch into the ejectornozzle so that the ejector may be operated by said exhaust gases, asuction conduit between the suction room of said ejector and the suctionside of said pump, means for increasing the suction efiect of saidejector and an arran ment for alternately opening and closing t edistribution chamber against the ejector and the open air.

5. In a device for evacuating pumps the comblnatlon of a pump, an eector having a nozzle and a suction room, an internal combustion enginehaving an exhaust branch, a

between the outlet of said exhaust branch and the inlet of said ejectornozzle, said distribution chamber having an outlet leading to the openair, said distribution chamber further being adapted to lead the exhaustgases of said internal combustion engine from its exhaust branch intothe ejector nozzle so that the ejector may be operated by said exhaustgases, a suction conduit between the suction room of said ejector andthe suction side of said pump, means for increasing the suction saidejector, said means comprising a wall located around the inlet of saidejector nozzle and transversely to' the flow of the exhaust distributionchamber gases, whereby these gases are compelled. to

utt against the said wall, and an arrangement for alternately openingand closing the distribution chamber against the ejector and the 0 enair.

-6. n a device for evacuating pumps accordin to claim 1 thefeaturethatthe ejector nozzlelias a sharp edged branching off from thewall, which is placed around the nozzle inlet transversely to the flowdirection of the exhaust gases.

7. In a device for evacuatingpumps according to claim 2 the feature thatthe ejector nozzle has a sharpedge-d branching olf from the wall, whichis placed around the nozzle inlet transversely to the flow direction ofthe exhaust gases.

8. In a device for evacuating pumps according to claim 5 the featurethat the ejector nozzle has a sharp edged branching oii. from the wall,which is placed around the nozzle inlet transversely to the flowdirection of the exhaust gases.

9. In a device for evacuating pumps the combination of a pump, anejector having a suction room, an internal combustion engine having anexhaust branch joined to the ejector so that said ejectormay be operatedby the exhaust gases of said internal combustion engine, a suctioncondluit be tween the suction room of said ejector and the suction sideof said pump, and a cooling device for cooling the exhaust gases priorto their entrance into the ejector.

10. In a device for evacuating pumps the combination of a pump, anejector having a a diffuser and a suction room, an innozzle, ternalcombustion engine having an exhaust branch, a connection between theoutlet of said exhaust branch and the inlet of said ejector nozzle, saidconnection being adapted to lead the exhaust gases of said internalcombustion engine from its exhaust branch into the ejector nozzle sothat the ejector may be operated by said exhaust gases,

conduit between the suction room of said a suction whereby these gasesvare compelled to butt 1 against said wall.

11. The combination of a device for evacusaid means comprising a walllocated ating pumps according to claim 2 and a cooling device forcooling the exhaust gases prior to their entrance into the ejector.

12. The combination of a device for evacuating pumps according to claim4 and a cooling device for cooling the exhaust gases prior to theirentrance into the ejector.

13. The combination of a device for evacuating pumps according to claim4 and a cooling device for cooling the exhaust gases prior to theirentrance into the ejector, said cooling device consisting of a coolingacket surrounding the distribution chamber and adapted to perm't thecirculation'of a cooling medium therethrough.

14. In a device for evacuating pumps the combination of a pump, anejector having a nozzle and a suction room, an internal combustionengine having an exhaust branch, a distribution chamber between theoutlet of said exhaust branch and the inlet of said cooling jacketthrough which a cooling m edium may circulate, a suction conduit betweenthe suction room of said ejector and the suction side of said pump,means for increasing the suction effect of said ejector, said meanscomprising a wall located around the inlet of said ejector nozzle andtransversely to the flow of the exhaust gases, whereby these gases arecompelled to butt against the a 'said wall, and an arrangement foralternately opening and closing the distribution chamber against theejector and the open air.

15. The combinationof a device for evacuating pumps according to claim1, characterized-by the provision of a cooling device for cooling theexhaust gases prior to their entrance into the ejector, and an ejectornozzle having a sharp edge branching off from the wall, which is placedaround the nozzle inlet transversely to the direction exhaust gases.

of flow of the 16. The combination of a device for evacuating pumpsaccording to claim 2, characterized by the provision of a cooling devicefor cooling the exhaust gases rior to their entrance into theejector,.an an ejector nozzle having a sharp edge branching ofi from thewall, which is placed around the nozzle inlet transversely to thedirection of flow of the exhaust gases.

exhaust branch, cha mber between the outlet of said exhaust branch andthe inlet of said ejector, said distribution chamber being provided withan outlet leading to the open air, a second outlet leading to the inletof the ejector nozzle, a cooling jacket through which a cooling mediumcirculates, and an arrangement for alternately opening and closing thedistribu- 'tion chamber against the open air and the ejector, a suctionconduit between the suction room of said ejector and the suction side ofsaid pump, and means for increasing the suction efl'ect of the ejector,said means comprising a wall located around the inlet of said ejectornozzle transversely to the flow of the exhaust gases, whereby thesegases are compelled to butt against said wall, said nozzle inletbranching off with a sharp edge from said wall, and an anteroom beforethe inlet of said ejector nozzle, said anteroom being limited at oneside by said wall.

In testimony whereof I aflix my signature.

FRANZ OBERASOHER.

